Designing a Multi-Region Disaster Recovery (Front Door + Failover)

Category: Reliability

Architecture diagram

High-level view of the main components and data/control flows.

Low-level architecture diagram (Visio-style)

Implementation view (networking, security, ops). Click to open full size.

Low-level architecture details

Step-by-step implementation

Step 1/6

Define RTO/RPO and topology

• Decide active-active vs active-passive.
• Define data replication requirements (SQL failover group, Cosmos multi-region).
• Define DR runbook ownership.

Validation checklist

• Stakeholders have signed off the scope, SLAs, and data/security requirements.
• You have documented naming standards, environments, and ownership (RACI).

Step 2/6

Deploy global entry (Front Door) and health probes

• Configure Front Door routing rules and backend pools.
• Set health probe paths and sensitivity.
• Enable WAF policies.

Validation checklist

• Deployment completed; smoke tests passed; rollback plan confirmed.

Step 3/6

Implement data replication

• For SQL: failover groups / geo-replication.
• For Storage: RA-GRS or object replication.
• Ensure secrets replicate (Key Vault backup/restore or multi-region strategy).

Validation checklist

• Failover procedure is documented and tested (tabletop + technical drill).
• RPO/RTO measured and meets requirements.

Step 4/6

Secure cross-region and access

• Use identical policies and RBAC in both regions.
• Keep private connectivity patterns consistent.
• Log and alert on failover actions.

Validation checklist

• Security baseline applied (Defender/Policy/WAF/Firewall rules as applicable).
• No public endpoints unless explicitly approved; private endpoints verified where applicable.
• Alerts are configured for high-risk events.

Step 5/6

Failover automation and observability

• Automate failover through runbooks (Automation/Functions).
• Create dashboards that show regional health and replication lag.
• Alert on probe failures and lag thresholds.

Validation checklist

• Logs and metrics are flowing (check Log Analytics / Monitor).
• Alerts trigger correctly (test alert path to email/Teams/ITSM).

Step 6/6

Run DR drills

• Quarterly failover tests with documented results.
• Validate DNS/Front Door routing, app behavior, and data integrity.
• Improve runbooks after each test.

Validation checklist

• UAT completed with representative users and scenarios.
• Performance meets baseline; issues tracked and remediated.

Video tutorials

• Build scalable apps with Azure cross-region Load Balancer (Azure Friday)
• Azure Friday playlist (search for Site Recovery / DR)

References

• Azure Front Door documentation
• Reliability guidance